Measurement of the νμ charged-current quasielastic cross section on carbon with the ND280 detector at T2K

This paper reports a measurement by the T2K experiment of the ν_μ charged current quasielastic (CCQE) cross section on a carbon target with the off-axis detector based on the observed distribution of muon momentum (p_μ) and angle with respect to the incident neutrino beam (θ_μ). The flux-integrated CCQE cross section was measured to be ⟨σ ⟩=(0.83 ±0.12 )×10^-38 cm² . The energy dependence of the CCQE cross section is also reported. The axial mass, M_A^QE, of the dipole axial form factor was extracted assuming the Smith-Moniz CCQE model with a relativistic Fermi gas nuclear model. Using the absolute (shape-only) p_μ-cos θ_μ distribution, the effective M_A^QE parameter was measured to be 1.2 6_-0.18^+0.21 GeV /c² (1.4 3_-0.22^+0.28 GeV /c² ).